Only now (PCIe 4 and very recent controllers etc) are the very latest top-end NVME drives hitting around 150k IOPS (which isn't stopping manufacturers from claiming ten times that; WD's NVME drive tests at around 150-200k IOPS and yet they claim 1M) and only in ideal circumstances...reads and writes coming out of the SLC cache, which typically under 30GB, often a lot smaller except in the highest-end drives.
Many drives that claim to reach that sort of performance are actually using Host Backed Cache, ie stealing RAM.
IOPS on SSDs drops precipitously once you exhaust any HBC, controller ram, SLC cache, mid-level MLC cache...and start having to hit the actual QLC/TLC. In the case of a very large database, a lot of IO would be outside cache (though certainly any index, transaction, logging, etc IO would likely be in cache.)
More than 500k IOPS was downright common for PCIe gen3 SSDs. 1M IOPS is totally achievable with one high-end gen4 SSD.
If you meant IOPS with a queue depth of one, or sustained write IOPS, then you need to specify those extra conditions before calling vendors liars.
No high-end drives implement the NVMe Host Memory Buffer feature, let alone rely on it for maximum performance.
You can buy an Enterprise QLC drive that is fully capable of 800k IOPS for reads. TLC drives that can do twice that are available. Those drives don't have SLC caching.
I would love to pick up from the 200k IOPS laptop quote and demo a RAM drive and then saturate the RAM drive into swapping - I don't know how you could do this on stock distros or Windows but it would make a great executive suite demo of the issues.
> “My laptop can do 200,000.”
Only now (PCIe 4 and very recent controllers etc) are the very latest top-end NVME drives hitting around 150k IOPS (which isn't stopping manufacturers from claiming ten times that; WD's NVME drive tests at around 150-200k IOPS and yet they claim 1M) and only in ideal circumstances...reads and writes coming out of the SLC cache, which typically under 30GB, often a lot smaller except in the highest-end drives.
Many drives that claim to reach that sort of performance are actually using Host Backed Cache, ie stealing RAM.
IOPS on SSDs drops precipitously once you exhaust any HBC, controller ram, SLC cache, mid-level MLC cache...and start having to hit the actual QLC/TLC. In the case of a very large database, a lot of IO would be outside cache (though certainly any index, transaction, logging, etc IO would likely be in cache.)